Swapping a Gen V LT engine into your Fox Body or SN95 Mustang? Speed Engineering's 1-7/8" LT swap longtube headers are built specifically for these platforms — mandrel bent, TIG-welded, and CNC-machined for a precise, port-matched fit on both the 1979–1993 Fox Body and 1994–2004 SN95 Mustang chassis. Compatible with 5.3L and 6.2L LT1, LT4, and LT5 engines. Dyno proven to deliver over 25 rear-wheel horsepower over stock manifolds.
Built from 304 natural stainless steel with merge spikes and standard graphite manifold gaskets included.
⚠️ Important Installation Notes:
- GM LT engine swaps only — these headers are NOT designed for Ford engines of any kind
- These headers have only been tested successfully with AJE Motor Mounts, Flaming River Steering Shafts, and AJE K-Members — compatibility with other combinations is unknown and not guaranteed
Features:
- Full 1-7/8" Port-Matched Primary Tubes with Merge Spikes — Full-diameter flow from cylinder head to collector for maximum exhaust scavenging
- 3" Collector with Merge Spikes — Optimized merge geometry for strong low-to-mid RPM torque
- Mandrel Bent Tubing — Consistent tube diameter through every bend; no crimping, no restriction
- CNC Machined Flanges — Precision fit at the cylinder head for a leak-free seal
- 304 Natural Stainless Steel Construction — Corrosion resistant, heat tolerant, and built to last
- Longtube Header Design — Maximum scavenging efficiency vs. shorty or mid-length headers
- Standard Graphite Manifold Gaskets Included
- Dyno Proven — 25+ RWHP gain on LT applications
- Compatible with 5.3L, 6.2L, LT1, LT4, and LT5 Engines
- V8 LT Engines Only
Vehicle Applications:
Note: All applications listed are GM LT engine swap conversions. These headers are not compatible with Ford engines of any kind.
Ford Mustang — Fox Body (RWD)
- 1979 Ford Mustang (RWD) — LT Swap
- 1980 Ford Mustang (RWD) — LT Swap
- 1981 Ford Mustang (RWD) — LT Swap
- 1982 Ford Mustang (RWD) — LT Swap
- 1983 Ford Mustang (RWD) — LT Swap
- 1984 Ford Mustang (RWD) — LT Swap
- 1985 Ford Mustang (RWD) — LT Swap
- 1986 Ford Mustang (RWD) — LT Swap
- 1987 Ford Mustang (RWD) — LT Swap
- 1988 Ford Mustang (RWD) — LT Swap
- 1989 Ford Mustang (RWD) — LT Swap
- 1990 Ford Mustang (RWD) — LT Swap
- 1991 Ford Mustang (RWD) — LT Swap
- 1992 Ford Mustang (RWD) — LT Swap
- 1993 Ford Mustang (RWD) — LT Swap
Ford Mustang — SN95 (RWD)
- 1994 Ford Mustang (RWD) — LT Swap
- 1995 Ford Mustang (RWD) — LT Swap
- 1996 Ford Mustang (RWD) — LT Swap
- 1997 Ford Mustang (RWD) — LT Swap
- 1998 Ford Mustang (RWD) — LT Swap
- 1999 Ford Mustang (RWD) — LT Swap
- 2000 Ford Mustang (RWD) — LT Swap
- 2001 Ford Mustang (RWD) — LT Swap
- 2002 Ford Mustang (RWD) — LT Swap
- 2003 Ford Mustang (RWD) — LT Swap
- 2004 Ford Mustang (RWD) — LT Swap
Frequently Asked Questions:
Q: Will these headers work with my Ford engine? No. These headers are designed for GM LT engine swaps only and are not compatible with Ford engines of any kind.
Q: What motor mounts and K-member are required for these headers? These headers have only been tested successfully with AJE Motor Mounts, Flaming River Steering Shafts, and AJE K-Members. Compatibility with other motor mount and K-member combinations is unknown and not guaranteed.
Q: What is the difference between these headers and the LS swap version for the same vehicles? The key difference is the engine family. Part 25-1166 is designed for GM Gen V LT direct injection engine swaps including LT1, LT4, and LT5. Part 25-1028 is designed for GM LS engine swaps including LS1, LS2, LS3, LS6, and LSA. Make sure you select the correct headers for your specific engine swap.
Q: Do these fit both Fox Body and SN95 Mustang chassis? Yes. These headers fit both the 1979–1993 Fox Body and 1994–2004 SN95 Ford Mustang platforms.
Q: What LT engines are these headers compatible with? These headers are compatible with GM Gen V LT V8 engines including 5.3L, 6.2L, LT1, LT4, and LT5.
Q: How much horsepower do these headers add? Speed Engineering's 1-7/8" LT swap longtube headers are dyno proven to add over 25 rear-wheel horsepower compared to stock exhaust manifolds on LT applications.
Q: What material are these headers made from? 304 natural stainless steel with full TIG-welded construction, CNC-machined flanges, and merge spikes.
Q: Are gaskets included? Yes. Standard graphite manifold gaskets are included with the headers.
Q: Are these headers street legal? No. These are race-only headers intended for closed-course competition use only. Installation on a street-driven vehicle may violate the Clean Air Act (42 U.S.C. 7522(a)(3)).
⚠️ Race Use Only: This product is manufactured and sold for installation on vehicles used solely for competition. Once installed, the vehicle may not be used, registered, or licensed for use on a public road or highway. Installation on a street-driven vehicle may violate the Clean Air Act 203(a)(3), 42 U.S.C. 7522(a)(3).